PRODUCTION OF SHAPED FILAMENTARY STRUCTURES

摘要

Duplex layers of carbon fibre each comprising a lower portion of uni-directional filaments and an upper staple fibre portion are laid one on top of the other in an annular form. Needles are reciprocated through the layers to cause the staple fibre to be pushed downwardly to interconnect the layers. The base supporting the layers being assembled is gradually lowered until there comes a time when the bottom of the needle stroke no longer passes through all of the layers. At that time additional layers comprising staple fibre only are added and needled down into the stack to enrich the lower layers. After that enrichment the stack is then built up by adding further duplex layers. When all of the duplex layers have been added, further staple fibres may be added to the stop of the stack and needled in order to enrich the upper layers with interconnecting staple fibres, which upper layers would otherwise be deficient in interconnecting staple fibre.